Technology Developer Accelerator Programme (TDAP)

Sigma Lithium: 3DLi technology – solving the dendrite problem

Has the issue of dendrite formation in Li-ion batteries finally been resolved? With at least 50 percent better performance achieved, one company supported through the Advanced Propulsion Centre’s (APC) Technology Developer Accelerator Programme (TDAP) believes it has done just that. 

An exciting route ahead towards more power-dense lithium-ion batteries is through the use of pure lithium metal anodes. However, dendrite formation in these next-gen lithium-ion batteries has long caused a serious conundrum for the future development of longer-range, faster-charging, and ultimately better EV batteries. The risk of short-circuiting and catastrophic failure that dendrites – small, tree branch-like growth formed by lithium on the surface of an anode (negative electrode) that slowly seeps into the battery material itself with repeated charge and discharge cycles – can cause, needs to be addressed before significant advancement in battery technology can occur. 

It was thought that solid-state batteries would be the solution, as they don’t contain liquid electrolyte and hence it was theorised, they would provide a physical barrier that prevents the formation of dendrites. However, studies showed that this was not the case, and as such the issue is still challenging the development of the next generation of solid-state batteries. 

Fortunately, that breakthrough may have just occurred, setting the stage for the next leap in capability for EVs.  

Sigma Lithium has developed a proprietary lithium metal anode with a porous 3D structure which is dendrite-free. The effect of this is that EV batteries using this anode can benefit from both higher charging and longer mileage. 

Dr Gleb Ivanov, CEO, Sigma Lithium, said:

Our 3DLi technology inside new generation Li batteries will enable mileage increase in EVs by 50% and it will not be compromised by fast charging, i.e., in 20 min as required by the industry.

“Sigma Lithium’s manufacturing process offers significant reduction in carbon footprint by 16% per kWh of a Li-ion battery produced due to the transition to dry coating methods offered by 3DLi technology”, added Daniel Kaute, advisor to Sigma Lithium. 

The company, which developed the technology with £135,000 of funding (£225,000 total project value) and business development support from the fifth TDAP cohort, focused its initial work on process innovation. This was achieved by optimising lithium coating methods on 3D scaffolds with high thermal stability. Subsequent trials demonstrated the feasibility and provided proof that it worked in trial batches of Li-metal cells.  

“The battery industry is experiencing a paradigm shift by moving away from wet-chemistry cells to solid-state components. We want Sigma Lithium to be a pioneer in that transition, especially in dendrite-free lithium anode materials. We are delighted to have the support of the APC in this journey, [and their help and funding] has enabled us to overcome one of the entry hurdles towards pre-commercial demonstration of stable cycle performance of porous metallic lithium anode in liquid electrolyte cells” said Dr Ivanov.

The sky’s the limit 

Following its success, the company is now operating a pilot facility to produce its porous electrode material. This will initially be involved with high-performance batteries in the aerospace sector, but is expected to ultimately end up targeting the £50 billion electrode market for electric vehicles. 

As well as the development of the porous 3D anode, Sigma Lithium has also benefited in other areas. Participating in TDAP and working with its business support mentors has enabled the business to improve its customer discovery and customer traction, enabled them to obtain a new patent, and also created new jobs within the team. 

“We have entered into a consortium agreement with a US customer, a US electrolyte supplier, and a German cell maker with the view to supply batteries with 3DLi technology to the specialist drone market in two and a half years,” reported Ivanov. 

Sigma Lithium is just one of over 100 companies to see success thanks to funding and support through TDAP. The programme helps SMEs, start-ups and spinouts with net-zero emission technology concepts to supercharge their route to market, with each participant receiving up to £170,000 of grant funding, with business mentoring provided, over an 18-month phased programme.